Make fluentd enabled configurable

Although there is an option "enable_fluentd", but there are still
some tasks that make fluentd not configurable.

Change-Id: Ic0a9deb36fce154022925d26411e01a8ffe18b50
Signed-off-by: Xinliang Liu <xinliang.liu@linaro.org>

ansible/roles/common/tasks/config.yml

@@ -80,12 +80,16 @@
     pattern: "*.conf"
   run_once: True
   register: find_custom_fluentd_outputs
+  when:
+    - enable_fluentd | bool
 
 - name: Copying over custom fluentd output config files
   template:
     src: "{{ item.path }}"
     dest: "{{ node_config_directory }}/fluentd/output/{{ item.path | basename }}"
   register: fluentd_output_custom
+  when:
+    - enable_fluentd | bool
   with_items: "{{ find_custom_fluentd_outputs.files }}"
   notify:
     - Restart fluentd container

ansible/roles/common/tasks/pull.yml

@@ -4,4 +4,6 @@
     action: "pull_image"
     common_options: "{{ docker_common_options }}"
     image: "{{ item.value.image }}"
+  when:
+    - item.value.enabled | bool
   with_dict: "{{ common_services }}"